| 摘要 |
PURPOSE:To produce colored Ti having no color difference with high work efficiency at a low cost by pickling a Ti material in a mixed aq. HF-H2O2 soln. having a specified concn., anodically oxidizing the pickled Ti material and keeping current density at a specified value until a prescribed electrolytic voltage is attained. CONSTITUTION:A Ti material is pickled and anodically oxidized to form an interference film on the surface of the Ti material and to develop color. When colored Ti is produced as mentioned above, the pickling is carried out in a mixed aq. HF-H2O2 soln. contg. 0.1-5.0wt.% HF and >=5 times as much H2O2 as HF. Before the pickling, primary pickling may be carried out in an aq. soln. contg. >=0.5% HF so as to previously remove smut. At the time of the anodic oxidation, current density is kept at a certain value within the range of 0.1-1.0A/dm<2> until a prescribed electrolytic voltage is attained. The oxide film is uniformly formed at ordinary temp. at a low cost without using nitric acid, etc., generating NOx, etc., and fine colored Ti is obtd. |
